Disable Smilies in This Post. Show Signature: include your profile signature. Only registered users may have signatures.

*If HTML and/or UBB Code are enabled, this means you can use HTML and/or UBB Code in your message.

If you have previously registered, but forgotten your password, click here.

T O P I C R E V I E W

Robert Pearlman

NASA release

SpaceX completes review of crew abort test

NASA partner Space Exploration Technologies (SpaceX) recently laid out its plan to demonstrate the Dragon spacecraft's ability to carry astronauts to safety in the event of an in-flight emergency.

This review of the in-flight abort test plan provided an assessment of the Dragon's SuperDraco engines, the software that would issue the abort command, and the interface between the Dragon spacecraft and the Falcon 9 rocket on which the spacecraft will be launched.

"It's critical to have a launch abort system in which NASA and SpaceX can have confidence," said Phil McAlister, director of Commercial Spaceflight Development at NASA Headquarters in Washington. "When you put humans aboard, safety and reliability are paramount and this review and the upcoming tests will help prove their space transportation system is on the right track."

Experts from NASA and the Federal Aviation Administration attended the review of the in-flight abort test plan Sept. 17, 2013 at SpaceX headquarters in Hawthorne, Calif. Attendees also had the opportunity to view the Dragon test spacecraft, which is being manufactured for an upcoming pad abort test and, potentially, the in-flight abort test.

"With NASA's support, SpaceX continues to implement the necessary modifications to equip Dragon to fly crew," said Garrett Reisman, commercial crew project manager at SpaceX. "SpaceX and NASA believe in rigorous flight testing and we are looking forward to putting our SuperDraco launch abort system through these critical tests, starting with the pad abort test in the spring and followed by the in-flight abort test in the summer."

The in-flight abort test will take place along Florida's space coast. During the test, a Dragon spacecraft will launch on a standard Falcon 9 rocket and an abort command will be issued approximately 73 seconds into the flight. At that point, the spacecraft will be flying through the area of maximum dynamic pressure, or Max Q, where the combination of air pressure and speed will cause maximal strain on the spacecraft.

Dragon will be outfitted with about 270 special sensors to measure a wide variety of stresses and acceleration effects on the spacecraft. An instrumented mannequin, similar to a crash test dummy, also will be inside. The spacecraft's parachutes will deploy for a splashdown in the Atlantic, where a ship will be pre-positioned for simulated rescue operations. The test spacecraft will be returned to Port Canaveral by barge so data can be retrieved and incorporated into the system's design.

Robert Pearlman

NASA release

More fidelity for SpaceX in-flight abort reduces risk

Following the successful pad abort test in May, SpaceX began developing a plan that would move its in-flight abort test to provide higher fidelity data and reduce risk to future crews launched to the International Space Station in the Crew Dragon spacecraft. NASA and SpaceX agreed to consider this proposed change prior to the mishap of SpaceX's seventh commercial resupply services mission.

The change comes after the company's successful pad abort test May 6 demonstrating the effectiveness of the Crew Dragon launch abort system. SpaceX is using the data collected during the test to confirm analysis models and inform the final spacecraft design.

"Testing the actual flight design always results in higher fidelity data and ultimately reduces risk for later crew flights," said William Gerstenmaier, associate administrator of the Human Exploration and Operations Mission Directorate at NASA Headquarters. "This change supports a philosophy of testing as you fly, which our experience has shown to be a good strategy for development and complements well the earlier system information gained from the pad abort test."

SpaceX originally intended to refurbish the pad abort vehicle for use in the in-flight abort test it was targeting for later this year. But since the pad abort vehicle began production more than two years ago, SpaceX has refined the Crew Dragon's design, and the planned design now differs from the pad abort vehicle design.

As a result, using the pad abort vehicle to conduct the in-flight abort test would not provide the best quality data. SpaceX can further reduce risk for later crewed flights and improve the fidelity of the data by using a Crew Dragon built to the current design.

"This is the kind of innovative, flexible thinking we want from our partners," said Kathy Lueders, manager of NASA's Commercial Crew Program. "The safety of our astronauts is paramount, and we are very happy that our partners are strategically re-assessing their plans for efficiencies."

In the updated plan, SpaceX would launch its uncrewed flight test (DM-1), refurbish the flight test vehicle, then conduct the in-flight abort test prior to the crew flight test. Using the same vehicle for the in-flight abort test will improve the realism of the ascent abort test and reduce risk. Further, the test would be performed from Kennedy Space Center's historic Launch Complex 39A instead of from Vandenberg Air Force Base.

The in-flight abort test is part of NASA's Commercial Crew Integrated Capability Space Act Agreement with SpaceX, so the updated plan would entail extending that agreement. No changes would be made in the milestone content, and NASA would incur no additional expense associated with moving the test date. SpaceX's planning indicates the company can implement the new plan without affecting its October 2017 certification date for the Crew Dragon and crew transportation system as part of its Commercial Crew Transportation Capability contract with NASA.

SpaceX has consulted with NASA on this new plan, and the company should complete its full assessment of the new plan and present its findings, including the new in-flight abort test date, to NASA within the next few weeks. NASA then will review the new plan and likely approve it, unless there is some technical issue.